A pressure sensor (or transducer) converts a fluid or gas pressure to an electrical signal as a function of the pressure imposed. These sensors are generally embodied in pressure sensor packages, and include a pressure-sensing device such as a silicon die. Such devices are typically manufactured using micro-machined or Micro-Electro-Mechanical System (MEMS) based techniques. One common technique for manufacturing a pressure sensor package is to attach a MEMS device onto a substrate, such as a ceramic or printed circuit board (PCB) substrate, via an adhesive. Enabling circuit components such as application-specific integrated circuits (ASICs), as well as conductive bonding pads and/or electrical traces, may be mounted to or formed on the substrate for electrically connecting to the MEMS device to perform desired functions (e.g. analog to digital conversion and/or amplification).
Silicon and/or other semiconductor materials used to form the pressure sensing device, however, have coefficients of thermal expansions (CTEs) that are significantly different than those of the ceramic or PCB materials used to form the substrates. This CTE mismatch can lead to inaccurate pressure measurements due to strain placed on the sensing device resulting from environmental temperature changes. Moreover, the adhesives used to attach the MEMS device to the substrate are subject to failure, particularly when exposed to harsh or corrosive media. For example, in applications which expose the sensor to harsh or corrosive media (e.g., in a fuel pressure sensing application), the adhesive can break down and ultimately fail. Likewise, as the substrate is typically adhered to a housing of a pressure sensor package, this junction is also subject to the same risk of failure when used in harsh or corrosive environments.
Alternative sensor systems and methods of manufacture thereof are desired.